Machine for polishing metal powders



y 7, 1940- H. H. MANDLE v 2.199.707

MACHINE FOR POLISHING METAL POWDERS Filed Feb. 25, 1937 2 Sheets-Sheet 1 I J 18 O 7 9!Jj:* 4 9 4- .94

5 5 5 5 5E xwmummmwwwwmwumAwmmuuwmumww muuuwmmumw INVENTOR Henry Ha man Mam/e.

ATTORNE Y5.

y 7, 1940- H. H. MANDLE 2.199.707

MACHINE FOR POLISHING METAL POWD ERS Filed Feb. 25, 1937 2 Sheets-Sheet 2 INVEN TOR. Henry Hayman Maud/e.

ATTORNEYS.

Patented May 7, 1940 UNITED STATES PATENT OFFICE MACI IINE FOR POLISHING METAL OWDEBS Application February 25,

1937, Serial No. 127,798

13 Claims. (01. 51-2)- When polished metal powders are 'required', as for example for paint and like purposes, the polishing operation is usually performed by friction with brushes in a closed cylindrical drum by relative rotation between brushes and drum. To control the polishing operation, it is necessary to be able to regulate the pressure at which these brushes are urged against the interior wall of the drum by thrust springs. Hitherto this was efiected after opening the drum by tightening or loosening the thrust springs by means of adjusting screwsprovided for this purpose.

This mode of regulation has various disadvantages. In the first place it is difficult to obtain a uniform regulation of all the brushes. In addition, the opening of the drum constitutes an undesirable interruption in the manufacturing operation during which fresh air flows into the interior of the drum; in some circumstances the air may have an unfavourable effect on the material being handled and in some'case's there is even the risk of an explosion in view of the nature of the metal powder which is being polished.

According to the present invention, the adjustment of the brush pressure is effected from outside the drum without opening the drum by con trol means passing into the drum through a stufiing box. Conveniently, the drum can be provided with a hollow shaft projecting at least at one end of the drum and accommodating a control member or members associated with the brush or brushes.

In order that the invention may be more readily understood reference will now be made to th accompanying drawings, in which:

Fig. 1 shows a cross-section through one embodiment of the invention,

Fig; 2 is a corresponding longitudinal section and,

Fig. 3 shows an external end view.

Fig. 4 shows a detail.

Figs. 5' and 6 show fragmentary views of a dif ferent embodiment of the invention.

I The polishing machine illustrated is of the typ in which the polishing brushes 6 are rotated within a stationary drum I provided with the usual closable openings (not shown) either in the ends of the drum or in the periphery thereof, for the introduction of powder into or removal of the same from the drum. Extending concentrically with the cylindrical drum l is a hollow shaft 2 running in bearings 3,provided at the ends of the drum. At the right-hand end of Fig. 2. the shaft 2 is closed by the plate I8 and at the other end a sealing plate It is provided which has a central aperture for the passage of concentric shafts l and II. The sealing plate IS in conjunction with the adjacent end of the shaft 2 thus constitutes a stufllng box through which the control means pass into the drum. Adjacent the sealing plate IS a driving pinion is secured on the shaft 2 and serves for transmitting the rotation thereto from a suitable driving device, not shown. Rigidly mounted on the hollow shaft 2 within the drum i are radial arms 4 to which levers 5 are pivotall0 1y attached at H. The polishing brushes 6 are secured to these levers 5 and are urged against the inner wall of the drum by means of springs I. These springs are carried by rods 8 and their initial tension and the initial positions of the 16 levers 5 and brushes 6 relatively to the wall of the drum l are adjusted by means of nuts 20 threadedly engaging the outer ends of the rods 8. At their inner ends. the springs abut against shoulders 21 on the rods 8. The rods 8 extend through slots 22 in the hollow shaft 2 and are pivotally attached to discs 9 which are keyed on the shafts l0, II which are arranged concentrically within the hollow shaft 2. By rotating the shaft [0 or H relatively to the hollow shaft 2 the tension of the corresponding springs I can be adjusted and thus the pressure of the brushes 6 against the wall of the drum can be varied. If, as in the example shown, two groups of brushes are arranged in succession in the axial 3o direction of the drum.- then each can be independently moved in the radial direction and the pressure with which the brushes of the individual groups bear against the inner .wall of the drum can be regulated in the individual groups by the control shafts F10 and II respectively. These control shafts pass out through the closed end of the hollow shaft and there can be rotated with respect to the hollow shaft by means of handles l2 and I3. I The degree of the rotation and thus the pressure exerted by the brushes on the wall of the drum can be read off by means 'of scales [4 and pointers l5 and I6 arranged on the handles i2 and I 3 respectively. To afford a positive adjustment and to ensure the retention of the adjusted positions. the handles 12 and I3 are preferably rotated relatively to the hollow shaft 2 by means of nuts 23 on threaded rods 24 pivotally attached at 40 to the hub of the driving pinion Instead of utilising a relative rotation between the control shafts l0 and II and the shaft 2, the adjustment of the brush pressure could be effected by longitudinal displacement of the control shafts Wand Ii relatively to the hollow shaft 2.

An arrangement employing such longitudinal displacement is shown in Figs. 5 and 6. As'in Figs. 1 and 2 the brushes 6 are carried by levers 5 supported on radial arms 4 and on adjustable rods 8. These rods 8 are pivoted at their inner ends to flanges 3| on a sleeve 32 which is rotat- .shaft 33 passes out through the sealing plate l9 and its threaded end carries a threaded sleeve 36 with a hand wheel 31 by the rotation of which the shaft 33 can be caused to move longitudinally within the tube 2 and sleeve 32. As seen inFig.

5, the sleeve 32 is provided with cam-slots 38 in which engage pins 39 carried by the shaft 33.

Consequently, longitudinal movement of the shaft 33 results in rotary movement of the sleeve 32 with adjustment of the brushes 6 precisely as brushes and a rotating drum.

described above with reference to Figs. 1 and 2. In other respects, Figs. 5 and 6 correspond with Figs. 1 and 2 and accordingly, the identical parts which are indicated by the same reference letters. are not further described with reference to Figs. 5 and 6.

While in the foregoing the invention has been described with reference to rotating brushes within a stationary drum, the same control principle can also be employed with stationary It will be apparent that with the control arrangements described above, it is possible to adjust the brush pressure without opening the drum and thus without allowing the gaseous contents ofthe drum to escape. This is particularly desirable if it is necessary to perform the polishing operation in an inert atmosphere. In such a case, it'is also desirable to prevent leakage at the bearings 3 and in some circumstances it is vital to prevent the lubricant employed at the bearings 3 from coming into contact with the metal powder within the drum. It is then advantageous to utilise a bearing arrangement as shown in Fig, 4. The bearing 3, which may conveniently be a ball hearing as shown, is not mounted directly on the end plate 26 of the drum but is mounted in a housing 21 attached to the A gas-tight joint can be obtained.

end plate. between housing 21 and end plate 26 on the one hand and bearing 3 on the other hand, by welding. The bearing 3 is provided with the usual washers or packing rings 28 to form a seal between bearing 3 and shaft 2. The gaseous atmosphere for the drum is introduced through the conduit 29 into the housing 21 and passes into the drum through the clearance gap 30 left between the shaft 2 and the end plate 26 of the drum. The pressure of the atmosphere in the housing 21 has the effect of preventing lubricant escaping past the inner packing ring 28 to the interior of the housing 21 and also tends to prevent the powder which is being polished within the drum from escaping through the gap 30 into the housing 21.

I claim:

1. A machine for polishing metal powders, comprising a closed cylindrical drum, a plurality of setsof brushes mounted within the drum for co-operation with the curved surface thereof. means for causing relative rotation of said brushes and drum, control'means for moving said sets of brushes towards and away from the curved surface and separate adjusting means external to the drum for operating the control means for each set of brushes, whereby the adjustment of the individual sets of brushes is effected from outside the drum without opening the drum.

2. A machine for polishing metal powders, comprising a closed cylindrical drum, a hollow shaft projecting from the drum at at least one end, a stuffing box at the projecting end of the shaft, a movable shaft supported within the hollow shaft and projecting from said stuffing box, fixed arms extending from the hollow shaft, arms movable substantially radially by said movable shaft, and brushes supported by said fixed and movable arms for co-operation with the curved surface of the drum.

3. A machine for polishing metal powders, comprising a closed cylindrical drum, a hollow shaft projecting from the drum 'at at least one end, a stufiing box at the projecting end of the shaft, a movable shaft supported within the hollow shaft and projecting from said stufling box, means external to the stuffing box for positively moving said movable shaft with respect to the hollow shaft, fixed arms extending from the hollow shaft, arms movable substantially radially by said movable shaft, and brushes supported by said fixed and movable arms for co-operation with the curved surface of the drum.

4. A machine for polishing metal powders, comprising a closed cylindrical drum, a hollow shaft projecting from the drum atat least one end, a stuffing box at the projecting end of the shaft, a plurality of sets of brushes supported for cooperation with the curved surface of the drum, a corresponding plurality of concentric control members arranged within said hollow shaft, means connecting the control members to the corresponding sets of brushes to enable movement of the latter with respect to the curved sur-- face of the drum, separate adjusting means associated with each control member externally of the drum, and means for causing relative rotation between brushes and drum.

5. A machine -for polishing metal powders within a closed cylindrical drum with the aid of brushes by relative rotary movement between brushes and drum, comprising a hollow shaft mounted axially in said drum to permit relative rotation between drum and hollow shaft, a closure member at one end of said hollow shaft, a stufling boxat the other end of said hollow shaft, a movable member passing into said hollow shaft through said stuffing box, means external to the stuffing box for rotating said member relatively to said hollow shaft, lateral projections on said member within said hollow shaft, movable arms pivoted to said projections and extending through slots in said hollow shaft, fixed arms extending from the hollow shaft and brushes supported on levers carried by said movable and fixed arms.

6. A machine for polishing metal powders within a closed cylindrical drum with, the aid of Uh RDHHUlNLJ,

ing rotation of said member with lateral projections by longitudinal movement of said movable member, movable arms pivoted to said projections and extending through slots in said hollow shaft, fixed arms extending from the hollow shaft and brushes supported on levers carried by said movable and fixed arms.

7. A machine for polishing metal powders, comprising a stationary closed cylindrical drum, a rotatable shaft mounted axially of said drum, means for rotatin the shaft, brushes supported on said shaft, yielding means for constantly urging said brushes outwardly towards the cylindrical surface of the drum, means operable from outside the drum for adjusting the brushes relatively to the cylindrical surface, and index means external to the drum for indicating the adjustment of the brushes within the drum.

8. Apparatus for polishing lamellar metal powders, including a closed cylindrical drum, brushes mounted within and cooperating with the curved surface of the closed cylindrical drum, means for producing relative rotary movement between brushes and the drum, springs for urging the brushes outwardly, stops for limiting outward movement of the brushes, and control means for positively moving the stops toward and away from the cylindrical surface including means passing out of the drum in a gas-tight manner.

9. Apparatus for polishing lamellar metal powders, including a closed cylindrical drum, brushes mounted within and cooperating with the curved surface of the closed cylindrical drum, means for producing relative rotary movement between brushes and the drum, brush holders supporting the brushes, fixed radial arms pivotally connected to the brush holders at one end of the latter, a shaft concentric with the drum, means disposed externally of the drum for operating the shaft, the operative connection be tween said external means and the shaft within the drum passing through the wall of the drum in a gas-tight manner, a radially extending member secured to said shaft, arms pivotally secured at their inner ends to said radially extending member, springs on said pivotally connected arms for urging the other ends of the brush holders outward, and stops on said arms for limiting outward movement of the brush holders, said stops being movable toward and from the shaft axis in response to turning of the shaft.

10. Apparatus for polishing lamellar metal powders, comprising a closed cylindrical drum, means for introducing powder into and removing it from the drum, a hollow shaft concentric with said drum, means for rotating the shaft, arms fixed to and extending outwardly from said hollow shaft, a shaft mounted within said hollow shaft. radially extending members secured to said inner shaft, outwardly extending pivotal arms eccentrically mounted on the radially extending members, brush carriers each extending peripherally of the drum between a fixed arm and a pivotal arm, means forming a pivotal connection between each brush carrier and the corresponding fixed arm, each brush carrier having sliding engagement with the corresponding piv otal arm, a stop on each pivotal arm limiting the outward movement of the associated brush carrier, a spring on each pivotal arm extending between a shoulder on the said pivotal arm and the associated brush carrier and urging the associated brush carrier outwardly towards its stop, brushes mounted on the brush carriers for cooperation with the inner cylindrical surface of the drum, and control means external to the drum operating on the inner shaft to rotate the latter in either direction to effect positive adjustment of the pivotal arms whereby the limiting stops are moved towards or away from the cylindrical surface of the drum, the operative connection between said control means external to the drum and the inner shaft within the drum passing through the wall of the drum in a gas-tight manner.

11. Apparatus as claimed in claim 10 in which the inner shaft passes out through a gas-tight gland at one end of the hollow shaft and is adjusted relatively thereto by a lever arm secured to the inner shaft, and adapted to be moved relatively to the hollow shaft by a threaded adjustment.

12. A machine for polishing metal powders comprising in combination, a substantially cylindrical drum having solid end walls and a solid peripheral portion connecting said end walls, an axial shaft passing through and extending beyond said end walls, polishing means secured to said shaft and disposed adjacent said peripheral drum portion, at least one of said end walls being provided with a central aperture through which the shaft passes with substantial clearance, a casing secured to said one end wall along the outer face thereof and spaced radially from said central aperture so as to form a gas-tight joint therewith and surrounding the shaft outside the drum, a bearing for the shaft directly secured to the outer end of said casing, means carried by said bearing for engaging and forming a seal with the shaft and means for introducing a gaseous medium into said casing.

13. The combination as set forth in claim 12 in which the means for introducing the gaseous medium comprises a stationary conduit connected to said casing and the means forming a seal with the shaft comprises an annular packing ring carried by that end of the bearing which is adjacent to said one end wall of the drum.

HENRY HAYMAN MANDLE. 

